The present invention relates to the merging of two streams of flat paper products, and more particularly, to an apparatus and method for merging two separate streams of printed signatures into a single shingled stream.
Since the advent of modern printing, printing presses and the associated machinery adapted for finishing a printed product, e.g. slitting, folding, trimming, collating and binding, have become faster and more efficient in operation. For example, when printing folded flat signatures or other forms of flat paper products, a web offset press usually runs at speeds ranging from 600 to 2000 feet a minute. These modern web presses also typically incorporate a former-folder which has the capability of folding and then longitudinally slitting the printed paper products, to form two parallel streams of resulting paper products.
From the former-folder, the two streams of paper products are fed to a finishing line, which forms the paper products into finished products. However, modern finishing lines can only accommodate one stream of the paper products, and thus in cases where the former-folder produces two parallel streams of paper products, two duplicate finishing lines must be incorporated downstream of the former-folder in order to process both streams concurrently, which requires a large capital investment. Alternatively, one of the streams is processed on a single finishing line, and the other parallel stream is bundled and held for later finishing. As will be apparent, this latter procedure results in the loss of time and economy in production.
With the foregoing in mind, it is an object of the present invention to provide an apparatus and method for effectively merging the two separate high speed streams of flat paper products which exit a former-folder, into one stream of products which can then be delivered to a single finishing line.